fuel boils in carb after turning off.

A heat insulator is a generally a good idea.
I use an 3mm Edelbrock insulator on top of my Edelbrock Performer and I can still fit the aircleaner under the screen (but only just).

Yup. The insulator (along with a slight adjustment to the floats) got rid of my boil-over problem. I'm running an Edelbrock 4V Performer with a 1/2" phenolic spacer. I have an Edelbrock cast aluminum "oval" air cleaner and the top of the air cleaner is dead even with my decklid (I don't have an engine screen)

Swen

Exactly ... I learned that a long time ago not to bolt a carb to the intake. heat transfer is dangerous with gasoline. There is also a spacer about 1/4" thisck that is made of a thick gasket material with little steel sleeves in the corner where the bolts go ...that one I think was factory BOSS 302 stuff.

Ron

Good phenolic spacers are widely available, Summit, Jegs, etc all have them. Use the largest that will fit, I ran the 1/2" 4-hole model to promote velocity. The B2 spacer is unique in that it has a metal tube exiting from the front of it that runs to the PCV in the rear of the right hand valve cover. In terms of insulating properties, there are much better spacers now available. Good luck..

I hear it also stops vapor lock.

[QUOTE]Originally posted by Rapier:
A heat insulator is a generally a good idea.

When I had a holley, my car boiled fuel all the time. You could even hear it. I had the carb mounted right on the intake. I first tried a multiple plate/gasket thing that worked so-so. Best is to use a plastic or phoenelic insulator. One with 4 holes works best and if only 1/2 inch thick, it still let the carb stay under the screen. Best solution is to switch to EFI.